Astronauts Say Tricky Space Station Repair a Success

NASA astronauts Tracy Caldwell Dyson (left) and Doug Wheelock work to set up the ammonia spare pump module after it was installed on the S1 Truss during an Aug. 16, 2010 spacewalk outside the International Space Station. It was the third spacewalk dedicated to the repair.Credit: NASA TV

"As
far as we can tell, things are coming back up nominally," Caldwell Dyson
said, adding that the station's U.S, Japanese and European labs are up and
running. "We've got most of our lab back ? so, to us here on orbit, things
are looking better than normal."

The
space station is home to six astronauts; three Americans and three Russians.

Emergency
space station repairs

During
three spacewalks, Wheelock and Caldwell Dyson removed the faulty ammonia pump
and replaced it with one of four spares stored on the exterior of the International Space Station. Walker operated the robotic arm from inside the
space station. [Graphic:
The International Space Station Explained]

"It
demonstrates how we can respond in an emergency," Walker said during the
interview with CBS News broadcast on NASA TV. "I think it was really NASA
at its finest to get this repair done in short order."

And
while these types of major repairs could become more complicated following the
retirement of NASA's space shuttle fleet, the ability for the ground
controllers and station astronauts to mobilize and complete such a task in a
short timeframe highlights the strong cooperative effort of those involved, the
astronauts said.

"It
was a validation of our teamwork, our training and everyone involved,"
Wheelock said. "The way everything came together was a great lesson in
teamwork. I think the confidence is real high on the team as we press
forward."

Practice
makes space perfect

To
plan and practice the spacewalks ahead of missions, astronauts rehearse the skills
and maneuvers in the Neutral Buoyancy Laboratory (NBL), a huge underwater tank
at Johnson Space Center in Houston.

"Our
training in the NBL back in Houston is skills-based," Wheelock explained.
"And those skills came in very handy. But when you get outside with the
temperature changes and the pure vacuum out there, things don't behave as they
do on Earth. We have to be ready for those things."

For
Walker, that meant remaining confident in her expertise at operating the
station's robotic arm.

"Just
like with the spacewalk operations, I was trained sort of generically,"
Walker said. "With the final EVA, I didn't get the procedures until the
day of."?

During
the first spacewalk, a stuck ammonia hose, and later an ammonia leak, gave Wheelock and Caldwell Dyson some
trouble when it refused to budge.

"I
think the greatest thing that I learned on my earlier EVAs (extravehicular
activities) is just to expect that," Wheelock said. "Just take a deep
breath, think of the different ways that you can finesse the piece of hardware,
and listen to what the trainers are telling you on the ground. And don't give
up trying."

For
the spacewalkers, the stubborn hose acted as their nemesis, said Wheelock.

"We
needed a villain to fight against when we were out there," he said. "But
we were able to rise to the challenge as a team."

Unforgettable
spacewalks

The
set of three EVAs will likely resonate with Caldwell Dyson, as they were her
first spacewalks. Amid the demanding tasks, she took time to reflect on the
significance of the situation, and described the experience as
"awe-inspiring."

"The
first EVA was a culmination of 12 years of training," Caldwell Dyson said.
"It was a culmination of so much desire and years of training that it's a
feeling I'll never forget.

The
station is slated to keep flying through at least 2020, so spare parts will be
a major concern once NASA's space shuttles stop flying next year.

NASA
currently plans to fly two final shuttle missions (in November of this year and February 2011) before
retiring its three-shuttle fleet for good. The possible addition of a third
shuttle flight is being discussed by lawmakers.